Peptide barcode of multidrug-resistant strains of Neisseria gonorrhoeae isolated from patients in Thailand.

The emergence of multidrug-resistant strains of Neisseria gonorrhoeae constitutes a serious threat to public health. The present study aimed to investigate peptidome-based biomarkers of multidrug-resistant N. gonorrhoeae, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography tandem mass spectrometry (LC-MS). The peptide barcode database of multidrug resistant N. gonorrhoeae was generated from the whole-cell peptides of 93 N. gonorrhoeae isolated from patients in Thailand. The dendrogram of 93 independent isolates of antibiotic-resistant N. gonorrhoeae revealed five distinct clusters including azithromycin resistance group (AZ), ciprofloxacin resistance group (C), ciprofloxacin and penicillin resistance group (CP), ciprofloxacin and tetracycline resistance group (CT), ciprofloxacin, penicillin and tetracycline resistance group (CPT). The peptidomes of all clusters were comparatively analyzed using a high-performance liquid chromatography-mass spectrometry method (LC-MS). Nine peptides derived from 9 proteins were highly expressed in AZ (p value < 0.05). These peptides also played a crucial role in numerous pathways and showed a strong relationship with the antibiotic resistances. In conclusion, this study showed a rapid screening of antibiotic-resistant N. gonorrhoeae using MALDI-TOF MS. Additionally, potential specific peptidome-based biomarker candidates for AZ, C, CP, CT and CPT-resistant N. gonorrhoeae were identified.